Precision linear components, such as op amps, comparators, voltage references and AC/DC converters, include active components, such as transistors and diodes, the performance of which is influenced by stresses created by packaging and molding. FIG. 1 illustrates a conventional silicon die 2 having a number of bond pads 4 on a first surface 6. FIG. 2 illustrates a conventional injection molded package 8 in which silicon die 2 has been secured, typically using an epoxy adhesive, to the paddle portion 10 of a lead frame 12. Lead frame 12 includes leads 14 which are electrically connected to selected bond pads 4 by bond wires 16. This assembly is then encapsulated within a suitable molding compound 17 to create an injection molded IC device 18.
One of the problems with conventional packaging when dealing with linear (analog) and mixed-signal (analog and digital) integrated circuits is that offset shifts, as well as shifts of other component values, are often created largely due to packaging stresses, materials having mismatched coefficients of thermal expansion, plastic deformation of molding components, and hysteresis of die mounting materials which vary with temperature and variations in time. Shifts which occur during packaging or while in operation can reduce performance of the part and limit the applicability of the part.